2 replies to this topic

[Daniel89]

Hi, I have a simulation file with some adjust, recycle and set functions going on. The convergance criteria is somewhat strict, but it converges quite fast as long as the input variables is not changed too much.

 

I have quite a lot of design cases to look into, but the discrepancy between cases is not very large so it converges quite quickly and well within max iterations for the different functions.

 

The problem I get when I have set up the discrete type, design study cases and have put all the states in, it doesn't move from state 1 to state 2. All unit ops have converged and I cant find no errors.

 

So everything seems to go fine when I press run, but it doesn't move to the next case even though the case has converged.

 

Does anyone have any tips with regards to what conditions needs to be met before it jumps to next state? 

 

Thanks for any help! 

Best regards,

Daniel 

 

 

 

 

[Daniel89]

Image of the case study page: https://ibb.co/8MnQwL6 Everything in flowsheet has converged, but it doesn't go to state 2. 

 

added: 

 

I have checked everything on the flowsheet, and it has converged and seems fine, but however I notice the solver is switching between active and ready in the lower left corner. Can the issue be that something is still iterating without me seeing it, any tip of identifying what?

 

Maybe another approach to problemsolving is if someone knows what criteria needs to be fullfilled before the design study jumps to the next state? 

 

I would really like to use the case study tool to look at my design cases, or else it will involve a huge amount of work to get all data exported manually, so all help I can get is deeply appreciated.

Edited by Daniel89, 05 April 2022 - 04:26 AM.

[Daniel89]

I found out the issue, it was calc level on several spreadsheets which had to be manipulated to get the right calculation order, at some of the sheets was input for adjust functions.

 

Now the model is working, but it converges very slowly, There is in total 3 recycle loops and 4 adjust functions, I have tried to changel calc levels so that recycle loops converges first, before the adjust functions starts to work. 

 

If anyone can give me some tips or take a look at my model to change and optimize things I would really appreciate it. I can send the HYSYS model on mail or DM a onedrive link for it.

 

Thanks for any feedback,

Best regards,

Daniel

Edited by Daniel89, 07 April 2022 - 05:06 PM.